Large scale concave, compound curve projection screens are most commonly constructed of formed and painted perforated aluminum panels attached to a steel outer frame. This technology is not portable and is expensive and fragile. Such screens do not readily scale down to systems below 25 feet in diameter. Large scale mobile screen surfaces can be created with a fabric envelope covering a frame structure and then using a vacuum between the surfaces to create the desired shape. Fabric screen surfaces show a seam between adjacent panels and exhibit pillowing caused by the differential stretching of the fabric panel. Smaller screen surfaces are often made using shaped FRG (fiberglass reinforced gypsum) board (drywall) and joint compound or molded fiberglass. These solutions are again not mobile and have the additional issue of acoustical reflections that degrade the user experience. Lastly a modular spherical screen assembly exists, but requires color matching filler between the seams of each rigid module which is not only time consuming but eliminates portability.